Fluid pump



April 21,1942. R SULLNAN 2,280,272

FLUID PUMP Filed March 15, 1940 47- 57 j] a; l

49 17 292.. lf 1; 4/ l" 17 K V lNVEN'I OR 3 ALA/ B JULLjV/IN ATTORNEY Patented Apr. 21, 1942 1 I FLUID PUMP Alan P.- Sullivan, Elizabeth, N. 1., assignor to Cities Service Oil Company, New York, N. Y., a corporation of Pennsylvania Application May 13, 1940, Serial No. 334,718

7 Claims.

This invention relatesto fluid pumps and particularly to rotary positive displacement mixing pumps. It specifically concerns pumps adapted to mix fluids in constant predetermined proportions when the pressure of any one of the fluids entering the pump may be variable.

In my coperiding application, Serial No. 324,178, filed March 15, 1940, an improvement in fluid pumps was disclosed for obtaining a constant, volume discharge of a fluid from a pump by automatic means, when the suction pressure ofthe fluid entering the pump was variable.

, Also disclosed in the application was a combination of this constant volume discharge pump with a mixing pump, whereby a mixture of predeterminedproportions was obtained from the fluid is successively added to a constant amount I of another fluid, whereby a mixture is obtained which contains accurate proportions of a small amount of one fluid mixed with a large amount of another fluid.

If one of several fluids drawn into a mixing pump is available only at a variable pressure,

the proportion of that fluid in the resulting mixture will vary directly with its pressure. To obtain a mixture having a small amount of one fluid mixed with alarge amount of another fluid, if the fluid of small proportions is available only at a variable pressure, it is first necessary to adjust this pressure to a constant pressure before mixing pump regardless of variations in the pressure of any one oi. the fluid portions entering the pump. e

The pump disclosed in the present application is an improvement over the disclosure of appli-' cation Serial No. 324,178 in that a mixing pump has been designed which is more simple in construction due to the fact that a-single chamber is now used where formerly two or more pump chambers were required.

It is the primary Object of this invention to provide a pump with a single chamber which will automatically adjust the suction pressure of any one of several fluids entering the pump and then mix a definite proportion of this fluid with. definite proportions oi the other fluids.

In rotary pumps of the positive displacement type, the amount of each fluid drawn into the pump is determined by the location or the suction ports on the periphery of the pump chamber. To obtain a mixture having a small amount .of one fluid mixed with a large amount of anotherfiuid, the use of a pump with a single chamber has heretofore been unsatisfactory, due to the, fact that the suction ports cannot be located accurately enough along its periphery to give the predetermined proportions desired. For this reason it has been the practice, in order to obtain a mixture having a small amount or one fluid in another, to use a pump with two or more chambers in series; whereby, after the two fluids are mixed in the first chamber, the proportion 'of one of the fluids is decreased by adding more of the other fluid to the mixture in another chamber, and then repeating this process of dilution in the succeeding pump chambers until "a mixture of the desired proportions is obtained.

Another object of this invention is to provide a pump having a single chamber in which one mixing it with the other fluid. Adjusting the pressure of one fluid to a constant pressure'and then successfully adding another fluid to the fluid so adjusted has previously been performed only by the use of a pump having several chambers.

A'further object of this invention, therefore, is to provide a pump, having a single chamber which will automatically adjust the fluctuatin suction pressureof a fluid to a constant pressure and will then successively add another fluid to this original fluid in order to obtain a mixture containing small amounts of the original fluid mixed with large'amounts of the other fluid.

Other'and more specific objects of the invention will become apparent from the following detailed specification in connection with the accompanying drawing. Fig. 1 is a sectional view of a pump embodyin a preferred form of the invention, the section being taken through the center of the pump along line l-l of Fig. 2.

Fig. 2 is a sectional view of the pump shown in Fig. 1, taken through its chamber along line 22 of Fig. l.

Fig. 3 is a sectional view of a modified form of a pump taken similarly to the section as shown in Fig. 2.

This invention is intended to include all mixing pumps having a chamber of such design that when a circular rotor is used therein, at least two or more interconnected pumpcompartments will be formed, of which the first compartment will have apressure regulating port by which the v ryin pressure of a fluid drawn into this compartment of the pump will be adjusted to 'a predetermined pressure, prior to its being mixed with the other fluids. The preferred form of the invention is an elliptical rotary positive displacement pump having a circular rotor with eight blades, which is illustrated by Figs. 1 and 2. In the operation of this pump, one fluid is drawn in at a suction port, is compressed, and has its pressure adjusted to a predetermined pressure maintained at a pressure regulating port. A constant volume of this fluid is then mixed with a constant volume of a second fluid, and the resulting mixture is further compressed and discharged at an exit port.

. Referring to Figs. 1 and 2, a pump is illustrated having a housing 3 in which an elliptically shaped chamber 5 is centrally located. A circularrotor I is mounted in chamber 5 with the center of its shaft 9 below the major axis of chamber 5, the diameter of the rotor I being such that it will contact the bottom wall of chamber 5 along line H. with rotor I so located, two pump compartments I3 and I5 are formed on opposite sides of chamber 5 with a clearance space H connecting the two compartments at the top of chamber The center of rotor shaft 9 passes through the minor axis of elliptical chamber 5, thus making eight blades, l9, 2|, 23, 25, 21, 29, 3| and 33, that are arranged to slide in the slots as rotor 1 turns. The use of a rotor with eight blades in a pump of this type is preferred, but it has been found that the pump will operate with similar results if a rotor having four or more blades is used.

An end plate 35 fits over the end of housing 3 in order to enclose chamber 5. Attached to end plate 35 is an elliptically shaped blade guide 31 (shown in Fig. 2), similar to the shape of elliptical chamber 5, and mounted to have its major and minor axes lie along the major and minor axes of elliptical chamber 5. When the pump is assembled, blade guide 31 touches the edge of each blade in order to hold the blades against the wall of chamber 5. In housing 3, leading into chamber 5, are a suction port 39, a pressure regulating port 4|, another suction port 43, and a discharge or exit port 45. In locating the position of pressure regulating port 4| and suction port 43 in chamber wall 5, rotor I is turned to the position illustrated in Fig. 2 with blades and 21, I9 and 33 equidistant from the minor axis of elliptical chamber 5. In this position of the rotor, the right side of port 4| is aligned with the right side of blade 25, and the left side of port 43 is aligned with the left side of blade 21.

Attached to pressure regulating port 4| is an adjustable exhaust valve 41 which determines the pressure maintained at regulating port 4|. haust valve 41 comprises'a valve disc 49 -with a stem 5| {attached thereto, and resting in valve seat 53. A spring 55 around stem 5| presses a disc 49 against a seat 53. The pressure that disc 43 exerts on slot 53 may be varied by adjusting valve nut 51.

Grooves 53 and GI, located along the periphery of chamber 5, are connected to suction ports and 43 respectively.

into the chamber space between successive blades passing each suction port until this chamber space reaches the maximum volume obtainable in the particular pump compartment through which it is then passing. For example, whenrotor I rotating in a clockwise direction reaches the position illustrated in Fig. 2, the chamber spaces be-. tween blades 2| and 23, blades 29 and 3| are at maximum volumes; so groove 59 extends the period of suction through-port 39 until each blade reaches the position of bladejl, and groove 5| extends the pen'od' of suction through port 43 until each blade reaches the position of blade 29.

In the operation of the pump, as rotor I turns in a clockwise direction, blade l9 moves upward drawing fluid A through suction port 39 into the chamber space between blades l9 and 2|, until blade l9 reaches the position of blade 2| in Fig, 2. As rotor I continues to turn, fluid A is compressed until blade l9 reaches the position of blade 25. The pressure of fluid A is adjusted to the pressure maintained at port 4| as the fluid A passes this port. The function of pressure regulating port 4| is to adjust the pressure of the fluid passing the port to a constant pressure; thus any fluid drawn in at suction port 39 at "a fluctuating pressure will have its pressure adjusted to a constant pressure when passing regu ating port 4|.

When blade 9 reaches the position of blade 25, a definite volume of fluid A at the predetermined pressure of port 4| is in the chamber space between blades l9 and 2|. This volume is determined by the amount of clearance between rotor I and the wall of chamber 5. Fluid A is 41 should be adjusted to permit a small flow offluid A through opening 63 when the pressure of fluid A entering suction port 39 is at the lowest pressure at which it will be available. This will insure a constant pressure at relief port 4|.

In designing the pump to obtain definite proportions of each fluid in the resulting mixture, the amount of clearance I! will determine the ,volume of fluid A that will be mixed with fluid B. This clearance I! can be increased or decreased by lowering or raising the location of I the axis of rotor shaft 9 with respect to the major axis of elliptical chamber 5 and simultaneously decreasing or increasing the diameter of rotor I in order that the outer periphery will contact the bottom wall of chamber 5 along line H. Therefore, with fluid B entering at a constant-pressure and volume, and being able to add any definite volume of fluid A at a constant' v the pump when passingregulating port 4|. Fluid The purpose of these B should also be available'at a constant pressure in order to have a constant proportion of fluid B in the mixture of fluid A and fluid B.

Illustrated by Fig. 3 is a pump of another form embodying the invention. The construction of this pump differs fundamentally from the construction of the pump shown in Figs. 1 and 2, by

the design of the pump chamber.

' spectively.

The pump chamber is or such a shape that tour pump compartments connected together by clearance spaces, will be formed when a circular rotor is placed therein. It is intended that the scope of this invention also shall-includev pumps having a single chamber designed to have three, five, six or more compartments which'will be connected in series by clearance spaces when a circular rotor is placed in the-pump chamber. The design and construction of such pumps will be similar to the pump illustrated in Fig. 3, whose structure and operation will now be described.

A housing 55 has a chamber 91 centrally lo- .cated therein. A rotor 99 having twelve slots holding twelve blades is mounted in housing 95 to rotate in chamber 51. When rotor 69 is placed in chamber 61, four pump compartments H, 13, 15 and 11 are formed with clearances 19, 9| and 93 connecting these compartments together in series. Rotor 99 is so located in housing 65 that The pump illustrated in Fig. 3 is designed speciflcally to be operated for adjusting. the variable pressure of one fluid, and then successively adding another fluid to this fluid. In operating thepump for this purpose, rotor 69 turns in a clockwise direction, drawing a fluid A into its outer periphery will contact the bottom wall of chamber 91, along line 95, thus separating compartment II from compartment 11. Although .all the compartments formed in chamber 51 are illustrated as having equal volumes, the location of rotor 69, and the shape of chamber 01, can be such that all the compartments will have different volumes, depending upon the desired application of the pump.

the space between blades H3 and H5, through suction port 9|, until blade I I3 reaches the end of groove I3I. The fluid is then compressed, having any variations in its suction pressure adjusted to the pressure maintained at regulating port 99 until blade II3 reaches the position of blade II1. carried into compartment 13, is determined by clearance 19. As rotor59 continues to turn, fluid B is drawn in between blades H3 and H5 at suction port 93 and mixed with fluid A until blade An end plate 81 (not shown), which is similar to the one illustrated in Fig. 1, is attached to housing 65 in order to close chamber 91. A blade guide 99 is attached to the end plate. The shape of blade guide 99 is similar to the shape of chamber 61, and serves to keep the blades against the wall of the chamber. There are four suction ports 9I, 93, 95 and 91; three pressure regulating ports, 99, MI and I03; and one discharge port I05, in housing 95, leading into chamber 61. To each of the pressure regulating ports 99, IM and I03, are connected relief valves I01, I09 and III, respectively, for maintaining a constant pressure at the pressure regulating ports. These relief valves are of the same construction as'relief valve 91, illustrated in Fig. 2. a

In locating suction ports 93, 95 and 91, and pressure regulating ports 99, IN and I03, a somewhat similar method is employed as was used to locate suction port 9| and pressure regulating port 93 in thepump of Fig. 2. Rotor 69 is turned to the position illustrated in Fig. 3, such that blades HI and I23, H3 and I29 are equidistant from a vertical line through the center of the axis of rotor 09. The upper side of blade H1 is aligned with the upper side of regulating ports is, aligned with the lower side of port I03; and

the upper side of blade I21 is aligned with the upper side of port 91.

By locating the suction ports and pressure regulating ports in these positions, one blade is just past a pressure regulating port when the preceding blade is just starting to pass the next suction port. Connected to suction ports 9|, 93, 95 and 91 are grooves'I3I, I33, I andl31 re- These grooves are located in the same manner as the grooves in the pump of Fig.

2. They are so located inthe wall of chamber 91 to permit fluid to be drawn through the suction ports into the chamber spaces betweemsuccessive II3 reaches the end of groove I33. This mixture then passes regulating port IOI where part of the mixture is discharged from vthe pump. Theamount of fluid which'is held between the blades H3 and H5 when blade II3 reaches the position clearance 8 I of blade I2I will depend upon the amount of This mixture is then brought into compartment 15 where some more of fluidB is drawn in at port 95. The mixture then passes port I03 where part is discharged and the remainder is brought into compartment 11 where more of fluid B is drawn in at port 91 to be added to the mixture. The finished mixture of fluid A and B is compressed and discharged at port I05.

For example, a pump may be so designed that the maximum capacity of the chamber space hetween blades I I3 and I I5 for each compartment is 100 cc., and the volume of the clearances 19, III and 93 is 10 cc. In the operation of the pump, after the pressure of fluid A is adjusted at port 99, 10 cc. of fluid A will be brought into compartment 13 to be mixed with cc. of fluid B drawn in'at suction port 93. As 10cc. or 10% of this mixture will enter compartment 15, then 1 cc. of fluid A and 9 cc. of fluid B will enter compartment 15, to be mixed with 90 cc. more of fluid B, drawn in at suction port 95. A mixture of 1 cc. of 'fluid A and 99 cc. of fluid B will leave compartment 15 of which 10% will pass intocompartment 11 or 0.1 cc. of fluid A and 9.9 cc. of fluid B will enter compartment 11. 'Then '90 more cc. of fluid B will be drawn into compartment 11 through suction port 91, to be mixed with the fluid coming from compartment 15. The resulting mixture leaving at'discharge port I05 will consist oi 0.1 cc. of fluid A, and 99.9 cc. of guid B, or one part or fluid A in 999 parts of fluid Fluid B should be-available for ports 93, 95 and 91 at a pressure equal to or greater than the pres sure maintained at relief valves I01, I09 and III.

In designing the pump in Fig. 3 for mixing The volume of fluid A which will be then' four diiferent fluids in definite proportions of each while adjusting the variable pressure of one of said fluids, the regulating ports NH and H13 are not used; and pump chamber'Gl is so shaped that when rotor 69 is placed therein, the compartments formed are not of equal volume, but

.each compartment increases in capacity, starti ing with compartment H and going in a clock- .drawn in at suction port 93.- The amount of fluid B drawn into the pump is determined by the volume of compartment 13. This volume of fluid B will be equal to a maximum chamber space between successive blades, less the volume of fluid A. The mixture of fluid A and fluid B then enter compartment 15 where fluid C is drawn into the pump through suction port 95. The volume of fluid C drawn into the pump will be equal to the maximum chamber space between successive blades, less the volume of fluids A and B. The mixture of these three fluids then enters compartment 11 to be mixed with fluid D, drawn into the pump through port 91. The amount of fluid D drawn in will equal the volume of the maximum chamber space between the blades, less the combined volumes of fluids A, B and C. The resulting mixture is compressed and discharged through port I05.

Relief valve In! should be adjusted to have a a small discharge of fluid A, when fluid A enters the pump at the lowest suction pressure at which it will be available,

The invention having been thus described, what is claimed as new is:

l. A fluid mixing pump comprising a housing, a chamber contained therein, a rotor having radial slots mounted to rotate in said chamber, a plurality of blades slidably mounted in the rotor slots, the side walls of said chamber being so designed as to form a guide face for the outer edge of the blades which is eccentrically placed with respect to the rotor and which is shaped so as to touch the circumference of the rotor at one sealing zone only and so as to alternately recede from and approachthe circumferencc of the rotor without touching at other points to form a'series of connected compartments in open communication with each other, a pressure regulating port in the compression side of each compartment, a suction port in each compartment, and a discharge port in the last. compartment of the series.

2. A fluid mixing pump comprising a housing, a chamber contained therein, a circular rotor having radial slots mounted to rotate in said chamber, a plurality of blades slidably mounted in the rotor slots, the side walls of said chamber being so designed as to form a guide face for the outer edge of the blades which is eccentrically placed with respect to the rotor and which is shaped so a to touch the circumference of the rotor at one sealing zone only and so as to alternately recede from and approach the circumference of the rotor Without touching at other points to form a series of connected compartments between the inner wall of the housing and the outer wall of the rotor, at pressure regulating port in the compression side of each compartment except the last compartment of the series,

an exhaust valve connected to one of said pressure regulating ports, a suction port in each compartment, and a discharge port in the last compartment of the series.

3; A fluid mixing pump comprising a housing. a chamber contained therein, a rotor having radial slots mounted to rotate in said chamber, a plurality of blades slidably mounted in the rotor slots, the side walls of said chamber being so designed as to form a guide face for the outer edge of the blades which is eccentrically placed with respect to the rotor and which is shaped so as to touch the circumference of the rotor at one sealing zone only and so as to alternately recede from and approach the circumference of the rotor without touching at another point to form a' series of connected compartments between the rotor and the inner wall of the housing, a pressure regulating port in the compression side of the first compartment of the series, a suction port in each compartment, and a discharge port in the last compartment of the series.

4. A fluid mixing pump comprising a housing, a chamber contained therein, a rotor having radial slot-s mounted to rotate in said chamber, a plurality of blades movably mounted in the rotor slots, the side walls of said chamber 'being so designed as to form a guide face for the outer edge of the blades which is eccentrically placed with respect to the rotor and which is shaped so as to touch the circumference of the rotor at one sealing zone only and so as to alternately recede from and approach the circumference of the rotor without touching at other points to form a series of compartments between the inner wall of the chamber and the outer wall of the rotor which are connected together by clearance spaces, the cross-sectional area of said compartments being greater than the cross-sectional area of said clearance spaces, a pressure regulating port in the compression side of each compartmentexcept the last compartment of the series, a suction port in each compartment, and a discharge port in the last compartment of the series.

5. In a fluid mixing pump comprising'a housing, a chamber contained therein, a rotor having radial slots mounted to rotate in said chamber, a plurality of blades slidably mounted in the rotor slots, the side walls of said chamber being so constructed as to form a guide face for the outer edge of the blades which is eccentrically placed with respect to the rotor and which is shaped so as to touch the circumference of the rotor at one sealing zone only and so as to alternately recede r from and approach the circumference of the rotor without touching at other points to form a plurality of pump compartments, said compartments connected in series by clearance spaces between the rotor and the chamber wall, a pressure regulating port in the compression side of each compartment except the last compartment of the series, a suction port in each compartment, and a discharge port in the last compartment of the series.

6. In a fluid mixing pump comprising a housing, an elliptical chamber contained therein, a rotor having radial slots mounted to rotate in said chamber, said rotor mounted in a position oil the major axis and on the minor axis of the elliptical chamber touching the surface of the chamber forming two compartments connected together by a clearance space between the rotor and the chamber wall, a plurality of blades slidably mounted in said rotor slots, a suction port in each compartment, a pressure regulating port in the compression side of the first of the two compartpartment.

'1. A fluid mixing pump comprising a housing,-

a chamber contained therein, a circular rotor having radial slots mounted in the housing, a

plurality of blades movably mounted in the rotor v slots, said chamber being so designed as to form a guide facev for the outer edge of the blades which is eccentrically placed with respect to the rotor and which is shaped so as to touch the cir- 2,2so,272 v ments, and a discharge port in the other comcumference of the rotor at one sealing line only and so as to alternately recede from and approach the circumference of the rotor without touching at three other points to form four compartments which are connected together in series by clearance spaces, a suction port in each compartment, a pressure regulating port in the compression side of each of the first three compartments of the series, and a discharge port in the last compartment.

, v ALAN Pf SULLIVAN. 

